Is fuel consumption necessarily going to be higher after a remap?
Not even with turbo engines the fuel consumption need to get worse. I have a Saab 9-3 1.8 BioPower as my daily car, 175hp original with E85 (150hp on petrol). I did first chip it, or rather got myself a box that reprograms the car, easly to get back to original program that way, and later on I changed the injectors to larger ones.
Standard: 175 hp/265 NM
Now: 245 hp/ 365 NM
What happened to my car?
First, the power output with petrol is very close to the E85 output.
Second, well, during transport, motorway/freeway/highway with the cruice control engaged it uses less fuel then original. It works absolutly best on smaller roads with 70-90km/h speed limits, then it uses very little E85. If I use the extra power I got however..... Let's say that it is possible to tripple the consumption...
So adjusting you specific engine is more or less always a good thing, but with a normally asperated enging you will not see the type of performance increase as on a turbo charged car like my Saab. But smother dilivery of power, a few extra hp, a little higher momentum etc.